EDM SYSHP MINI DCI

64
3 Water Pipework
3.1 Water Circuit Checks
Mini Heat Pump Monobloc units are equipped with a water inl et and outlet for connecon to a water circuit. Mini Heat
Pump Monobloc units should only be connected to closed water circuits. Connecon to an open water circuit would lead
to excessive corrosion of the water piping. Only materials complying with all applicable legislaon should be used. Before
connuing installaon of the unit, check the following:
 The maximum water pressure ≤ 3 bar.
 The maximum water temperature ≤ 70°C according to safety device seng.
 Always use materials that are compable with the water used in the system and with the materials used in the unit.
 Ensure that components installed in the eld piping can withstand the water pressure and temperature.
 Drain taps must be provided at all low points of the system to permit complete drainage of the circuit during maintenance.
 Air vents must be provided at all high points of the system. The vents should be located at points that are easily accessible
for service. An automac air purge is provided inside the unit. Check that this air purge valve is not ghtened so that
automac release of air in the water circuit is possible.
3.2 Water Volume and Expansion Vessel Pre-pressure Checks
Outdoor units are equipped with an expansion vessel (5/7/9kW models: 2L; 12/14/16kW models: 5L) that has a default
pre-pressure of 1.5 bar. To assure proper operaon of the unit, the pre-pressure of the expansion vessel might need to be
adjusted. Refer to Table 3-3.1. The total volume of water in the system must be at least 25L(for 5/7/9kW unit, the minimum
volume is 15L) and should not exceed the limits specied in Figure 3-3.1.
Table 3-3.1: Expansion vessel pre-pressure adjustment
Installaon height dierence
1
Water volume ≤ X L
2
Water volume > X L
2
≤ 12 m
No pre-pressure adjustment required
Acons required:
•Pre-pressure must be decreased, calculate
according to “Calculang the pre-pressure of
theexpansion vessel”
3
•Check if the water volume is lower than
maximumallowed water volume (refer to Figure
3-3.1)
> 12 m
Acons required:
•Pre-pressure must be increased, calculate according
to “Calculang the pre-pressure of theexpansion
vessel”
2
•Check if the water volume is lower than
maximumallowed water volume (refer to Figure
3-3.1)
Expansion vessel in the outdoorunit too small for the
system. An external expansion vessel (eld suppied)
is required.
Notes:
1. Height dierence is between the highest point of the water circuit and the outdoor unit’s expansion tank. Unless the unit is located at the highest point of the
system, in which case the installaon height dierence is considered to be zero.
2. For 1-phase 12~16kW and 3-phase 12~16kW units, this value is 72L, for 5~9kW units, this value is 30 L.
3. Calculang the pre-pressure of the expansion vessel:
The pre-pressure (Pg) to be set depends on the maximum installaon height dierence (H) and is calculated as Pg(bar)=(H(m)/10+0.3) bar